Installing

Invoked via the following command (available since 0.47.0):

meson install

or alternatively (on older Meson versions with ninja backend):

ninja install

By default Meson will not install anything. Build targets can be installed by tagging them as installable in the definition.

project('install', 'c')
shared_library('mylib', 'libfile.c', install : true)

There is usually no need to specify install paths or the like. Meson will automatically install it to the standards-conforming location. In this particular case the executable is installed to the bin subdirectory of the install prefix. However if you wish to override the install dir, you can do that with the install_dir argument.

executable('prog', 'prog.c', install : true, install_dir : 'my/special/dir')

Other install commands are the following.

install_headers('header.h', subdir : 'projname') # -> include/projname/header.h
install_man('foo.1') # -> share/man/man1/foo.1
install_data('datafile.dat', install_dir : get_option('datadir') / 'progname')
# -> share/progname/datafile.dat

install_data() supports rename of the file since 0.46.0.

# file.txt -> {datadir}/{projectname}/new-name.txt
install_data('file.txt', rename : 'new-name.txt')

# file1.txt -> share/myapp/dir1/data.txt
# file2.txt -> share/myapp/dir2/data.txt
install_data(['file1.txt', 'file2.txt'],
             rename : ['dir1/data.txt', 'dir2/data.txt'],
             install_dir : 'share/myapp')

Sometimes you want to copy an entire subtree directly. For this use case there is the install_subdir command, which can be used like this.

install_subdir('mydir', install_dir : 'include') # mydir subtree -> include/mydir

Most of the time you want to install files relative to the install prefix. Sometimes you need to go outside of the prefix (such as writing files to /etc instead of /usr/etc. This can be accomplished by giving an absolute install path.

install_data(sources : 'foo.dat', install_dir : '/etc') # -> /etc/foo.dat

Custom install behavior

Sometimes you need to do more than just install basic targets. Meson makes this easy by allowing you to specify a custom script to execute at install time. As an example, here is a script that generates an empty file in a custom directory.

#!/bin/sh

mkdir "${DESTDIR}/${MESON_INSTALL_PREFIX}/mydir"
touch "${DESTDIR}/${MESON_INSTALL_PREFIX}/mydir/file.dat"

As you can see, Meson sets up some environment variables to help you write your script (DESTDIR is not set by Meson, it is inherited from the outside environment). In addition to the install prefix, Meson also sets the variables MESON_SOURCE_ROOT and MESON_BUILD_ROOT.

Telling Meson to run this script at install time is a one-liner.

meson.add_install_script('myscript.sh')

The argument is the name of the script file relative to the current subdirectory.

DESTDIR support

Sometimes you need to install to a different directory than the install prefix. This is most common when building rpm or deb packages. This is done with the DESTDIR environment variable and it is used just like with other build systems:

$ DESTDIR=/path/to/staging/area meson install

Custom install behaviour

Installation behaviour can be further customized using additional arguments.

For example, if you wish to install the current setup without rebuilding the code (which the default install target always does) and only installing those files that have changed, you would run this command in the build tree:

$ meson install --no-rebuild --only-changed

Finer control over install locations

Sometimes it is necessary to only install a subsection of output files or install them in different directories. This can be done by specifying install_dir as an array rather than a single string. The array must have as many items as there are outputs and each entry specifies how the corresponding output file should be installed. For example:

custom_target(...
    output: ['file1', 'file2', 'file3'],
    install_dir: ['path1', false, 'path3'],
    ...
)

In this case file1 would be installed to /prefix/path1/file1, file2 would not be installed at all and file3 would be installed to `/prefix/path3/file3'.